Weicon WEICONLOCK® AN 305-73 Flange Sealing Gasket

Weicon WEICONLOCK® AN 305-73 Flange Sealing Gasket is an anaerobic sealing product that acts as a gasket on metal flange surfaces. Thanks to its high-viscosity structure, it aims to fill gaps by forming a film on the flange mating surfaces without flowing. Since it is positioned in a low-strength class, it is suitable for applications where easier disassembly can be planned during maintenance. While meeting sealing needs in flange connections, it also forms a stable “formed-in-place gasket” between surfaces with an industrial-adhesive character within the process.

Formed-in-place gasket approach on flanges with WEICONLOCK AN 305-73
As an alternative to conventional cut gaskets, this product works on the “liquid gasket” principle on flange surfaces and is intended for use particularly on joints such as flanges, gearboxes, and motor housings. Due to its anaerobic chemistry, it cures where air contact is cut off between metal surfaces, creating a leak-tight layer. High viscosity increases control on the surface and helps the product remain in the joint line during application. Its low-strength nature helps parts be removed more easily with standard hand tools in maintenance and repair scenarios, which is a practical advantage for teams selecting an industrial adhesive based on serviceability.

Chemical structure, performance, and durability framework
AN 305-73 is a flange sealing material that cures anaerobically on metal surfaces and is formulated with a low-strength target. Technical data specify a temperature resistance range of -60 °C to +150 °C, offering a predictable operating band for many machine housings and flange connections. At room temperature, the initial fixture/handling time is given as approximately 20–40 minutes, and the time to reach final strength is about 12 hours, helping clarify commissioning timing in maintenance planning. A shear strength range of 4–6 N/mm² is stated; it should be considered that values can vary depending on the process, surface preparation, and gap geometry. These properties form the technical basis for choosing the product as a “sealing-focused industrial adhesive.”

Application method and correct process steps
Before application, removing oil, dirt, and loose layers from flange surfaces directly affects sealing performance. The product is applied evenly to the surface using the nozzle on the bottle/tube; avoiding contact between the dosing tip and metal helps achieve more controlled application. It is applied as a continuous bead on one flange surface, the parts are assembled quickly, and then fixed with the appropriate tightening torque. Since curing occurs within the joint surface, delaying assembly is not recommended; this approach supports the consistency of both the sealing and industrial-adhesive effects. On difficult-to-cure surfaces or where faster processing is needed, using an activator with the manufacturer’s accessories can be considered as an optional supporting step.

Industry applications and compatible systems
The product is typically used for sealing flange joints in gearboxes, motor housings, pumps, and general machinery equipment. In automotive and transportation, it is relevant for powertrain components; in industrial maintenance and repair, it provides a practical solution for housing covers, service flanges, and process equipment connections. Being low strength helps facilitate disassembly and reassembly operations in facilities with regular maintenance needs and can contribute to optimizing service times. In addition, being listed with ISSA and IMPA codes serves as a brief reference that helps correct product matching, especially in marine and industrial procurement processes. In this context, AN 305-73 can be positioned as an industrial adhesive/sealing solution focused on flange sealing while offering the advantage of removability.